The disclosure relates to an image processing method and apparatus. In more particular, the disclosure relates to an image processing method capable of detecting a target such as a person from an image having depth information and modeling the target.
A CCD camera serving as the important part of computer vision can read only a 2-D image. However, we live in a 3-D space, and, when the 3-D space must be recognized, only one camera providing a 2-D image is insufficient.
To attempt to extract 3-D information through a sensor of a camera that can receive only 2-D information, following various schemes have been developed until now.
First, there has been an attempt to measure the distance from an object by irradiating a laser beam onto the surface of the object and measuring time in which the laser beam is reflected from the object to a sensor. Although this scheme may be easily employed in order to measure the distance from the object spaced apart from the sensor by 15 m or more indoors, the resolution of 1 cm or less may not be expected. Accordingly, the scheme is not extensively used.
Second, there has been an attempt to irradiate light having a predetermined pattern onto an object to find the depth information thereof, and analyzing the distortion degree of a pattern appearing on an object surface, so that the curved degree of the object surface and the distance from the object are calculated. This scheme is the simplest scheme for implementation among other schemes. However, as the object is farther away from the camera, the resolution of the image is significantly degraded.
Third, there has been developed a scheme employing a Moire pattern. According to the scheme, light having the diffraction pattern is irradiated onto an object in order to measure the distance from the object in one direction, and the pattern of the light reflected from the object makes interference with a reference pattern in another direction. Then, the Moire pattern resulting from the interference is analyzed, so that the depth information of the object is extracted. Although the scheme employing the Moire pattern can bring the superior result representing the resolution of 10 μm, a huge amount of data computation is caused.
Fourth, there has been an attempt to irradiate a variety of lights onto an object, and detect the variation of an object surface representing various characteristics depending on the lights, thereby estimating the shape of the object. However, typical 3-D depth information cannot be extracted through this scheme.
The above schemes are to extract 3-D information by using only one camera.
Meanwhile, recently, a scheme employing two cameras by emulating the visual system of a human has been attempted.
In detail, through a stereo vision scheme employing at least two cameras, the depth information of an object can be acquired from the cameras by using the geometrical relation between left and right images taken by the two cameras and the matching relation between the left and right images. In the process of acquiring the depth information, the accurate and complex computation is required. However, in the present description, a method of detecting an object after the depth information of the object has been acquired and modeling the object will be described.